This invention relates to a method of photovoltaic device manufacture wherein a plurality of cells are connected in series at interconnect sites. It is critical to make the interconnect sites, where cells fabricated on a single transparent substrate are joined in series, as small as possible to maximize the effective power producing area of the photovoltaic device. Prior art which attains this objective by laser scribing cell interconnect sites is described by Japanese public disclosure 33477 (1987).
The series connected photovoltaic device fabrication technique described by this public disclosure is as follows. A transparent electrode layer 2 is established over the entire surface of a glass substrate 1 (FIG. 1). After dividing the electrode layer into a plurality of unit areas via laser scribe A (FIG. 2), lines of conducting paste 5 and insulating paste 6 are provided adjacent to the dividing cuts 3 (FIG. 3). Further, after annealing the paste, an amorphous silicon layer 7 and a surface electrode layer 8 are formed (FIG. 4). Finally, by laser scribing over the conducting paste 5, the surface electrodes 8 and transparent electrodes 2 of adjacent cells 2a, 2b, and 2c are connected electrically, and by laser scribing over the insulating paste 6, the surface electrode layer 8 and the amorphous silicon layer 7 are cut (FIG. 5) thereby connecting separate cells 2a, 2b, and 2c in series.
However, since this method also heats the transparent electrode layer 2 when the conducting paste 5 and insulating paste 6 are annealed, the transparent electrode layer 2 divided into unit areas by laser scribing can become reconnected, shorting cell divisions and reducing power conversion efficiency.
The present invention provides a method of photoelectric device manufacture in which the transparent electrode layer does not become reconnected as in the case of the former method described above.